Using a new IC is not identified as a Blinkstick


I replaced the IC of my original Blinkstick and programmed the firmware onto it with AVRdude using:

avrdude -c avrisp -P COM3 -p t85 -b 19200 -U flash:w:hqdkdTzX.hex:i
avrdude -c avrisp -P COM3 -p t85 -b 19200 -U hfuse:w:0xdd:m -U lfuse:w:0xe1:m

It connects via USB properly and shows up in the Blinkstick client but its name and serial number is ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ and I can’t use it with the client or a python script. Did I mess something up when programming it or do I just need to update a descriptor or something? Thanks.

Blinkstick Pro "Factory" Reset

Please take a look at this thread. I also had problems with the serial but it is a few month ago.

Hope it helps.


Do I have to upload the eeprom.hex by itself or was that included in the .hex I flashed but was wrong? I’m not very experienced in any of this so I appreciate your patience.

Also, I used not
would that make a difference?



It makes a different, because there are more than one blinkstick products. You need the Pro firmware.

Here are the steps I´ve taken to “repair” my attiny:

  • Install AVR toolchain
  • Install ruby (maype you need to set the PATH variable)
  • Download BlinkStick Firmware (Pro); unzip it
  • rename eeprom-default.hex to eeprom.hex
  • rename serial.txt-template to serial.txt
  • open cmd, cd to the firmware folder
    make clean hex
    make defaults
    make deploy


Where do I get the eeprom.hex for the pro firmware?


I think you could use this one:



I’m having a problem getting it to work… I renamed the files, and make clean hex an I got this
The problem is when I do avrdude -c avrisp -P com3 -p t85 -B 3 -b 19200 -U eeprom:w:eeprom.hex:i and avrdude -c avrisp -P com3 -p t85 -b 19200 -U flash:w:main.hex:i I get the same messed up serial number in the client.

make defaults and make deploy don’t work because I have to set the isp and com port. Also, I don’t know why I need -b 19200 but it won’t work without it.